Abstract:

The aim was to study the effects of photoperiod on membrane lipid peroxidation, antioxidant enzyme activities and other physiological indices in cucumber seedlings. The cucumber seedlings filled light 0, 3, 6, 9, 12 h at night were treated by 25℃ and 10℃ in order to study the effect of different photoperiod on cold resistance of cucumber seedlings. The results showed that: the chloroplast pigments content, soluble sugar and soluble protein content, CAT and POD activity in leaves of cucumber seedlings treated by 25℃ and 10℃, were increased with the fill light extension, but relative electrolytic leakage and MDA content decreased. Compared with 25℃, low temperature stress (10℃) reduced cucumber chloroplast pigment content, but increased relative electrolytic leakage , MDA, soluble sugar and soluble protein content, CAT and POD activity. The longer the photoperiod, the smaller the change ratio of chloroplast pigment content, relative electrolytic leakage and MDA content, the greater the change ratio of soluble sugar and soluble protein content, CAT and POD activity. Extending the illumination time could promote the accumulation of soluble protein and sugar, raise the activities of antioxidant enzymes, decrease the membrane lipid peroxidation and improve the cold resistance of cucumber seedlings.